E46 Post Cat Oxygen Sensor Replacement DIY  

That is true that’s probably what im going to do when i replace mine but hes not replacing his just removing them for whatever reason he needs to then hes reinstalling them

it should be *bank 2, sensor 1, heater circuit,* that's what I'm getting on my OBD2 scanner. unless both downstream sensors are both heaters?! weird.

Yep that's another option.

California checks to make sure you've got your catalytic converters during the 2 year smog check.

oh i had no idea you were in california! oh well, atleast you get nice weather and beaches!

No. You need to look at your fuel trims and figure out if you've got a lean condition and what type of lean condition it is. Watch my fuel trims video.

Check your fuel trims to see if they are normal. It's possible to have a false P0430 but very unlikely. If your trims are normal, you simply need a new cat. If they are not, correct whatever condition is making them rich or lean and then see if the P0430 comes back.

thanks. on a similar theme, ngk also make oxygen sensors i think both post and pre cat. can you see any issue with using those assuming they would be oem manufactured as alternative to bosch and are not as expensive? the analysis showed temperature was incorrect. can you comment about whether that may mean the sensors are damaged or the exhaust is too rich/lean?

hello jason .here is some data from torque. I ran the car for about 30 miles, did not turn engine off in city and some highway driving. No codes. all seems to check out although id did not loo at the fuel trims specifically, looking for some app to do that and record the data. But from what i can see including emission readiness all went through at least 1 drive cycle and no obvious issues. also from what i can see there are no pending codes either. Mode $06 report generated by Torque for Android ================================================ Vehicle VIN: Not present Vehicle Manufacturer: Unknown Vehicle Calibration ID: 7519308 7520559 Unit and scaling information are not supplied with the data from the ECU for this type of vehicle. Consulting the manufacturers service book for this information is recommended. Test report: ------------------ TID:$01 CID:$01 - Rich to Lean sensor threshold voltage(constant) Max: 328 Test result value: 312 PASS ---- TID:$01 CID:$02 - Rich to Lean sensor threshold voltage(constant) Max: 328 Test result value: 313 PASS ---- TID:$02 CID:$01 - Lean to Rich sensor threshold voltage(constant) Max: 1,229 Test result value: 328 PASS ---- TID:$02 CID:$02 - Lean to Rich sensor threshold voltage(constant) Max: 1,229 Test result value: 321 PASS ---- TID:$02 CID:$03 - Lean to Rich sensor threshold voltage(constant) Max: 65,535 Test result value: 389 PASS ---- TID:$02 CID:$04 - Lean to Rich sensor threshold voltage(constant) Max: 65,535 Test result value: 190 PASS ---- TID:$02 CID:$05 - Lean to Rich sensor threshold voltage(constant) Max: 1,229 Test result value: 276 PASS ---- TID:$02 CID:$06 - Lean to Rich sensor threshold voltage(constant) Max: 1,229 Test result value: 285 PASS ---- TID:$02 CID:$07 - Lean to Rich sensor threshold voltage(constant) Max: 65,535 Test result value: 384 PASS ---- TID:$02 CID:$08 - Lean to Rich sensor threshold voltage(constant) Max: 65,535 Test result value: 259 PASS ---- TID:$02 CID:$09 - Lean to Rich sensor threshold voltage(constant) Min: 104 Test result value: 105 PASS ---- TID:$02 CID:$0a - Lean to Rich sensor threshold voltage(constant) Min: 104 Test result value: 111 PASS ---- TID:$03 CID:$05 - Low sensor Voltage for switch time calculation Min: 0 Test result value: 65,535 PASS ---- TID:$03 CID:$06 - Low sensor Voltage for switch time calculation Min: 0 Test result value: 65,535 PASS ---- TID:$05 CID:$07 - Rich to Lean sensor switch time(calculated) Min: 3,932 Test result value: 3,941 PASS ---- TID:$05 CID:$08 - Rich to Lean sensor switch time(calculated) Min: 0 Test result value: 65,535 PASS ---- TID:$05 CID:$12 - Rich to Lean sensor switch time(calculated) Min: 0 Test result value: 65,535 PASS ---- TID:$05 CID:$15 - Rich to Lean sensor switch time(calculated) Min: 0 Test result value: 65,535 PASS ---- TID:$05 CID:$16 - Rich to Lean sensor switch time(calculated) Min: 0 Test result value: 65,535 PASS ---- TID:$05 CID:$18 - Rich to Lean sensor switch time(calculated) Min: 0 Test result value: 65,535 PASS ---- TID:$06 CID:$01 - Lean to Rich sensor switch time(calculated) Max: 3,600 Test result value: 908 PASS ---- TID:$06 CID:$02 - Lean to Rich sensor switch time(calculated) Max: 3,600 Test result value: 73 PASS ---- TID:$06 CID:$03 - Lean to Rich sensor switch time(calculated) Max: 3,600 Test result value: 177 PASS ---- TID:$06 CID:$04 - Lean to Rich sensor switch time(calculated) Max: 3,600 Test result value: 43 PASS ---- End of report.

Sony AX53

Also, I've bought a euro car parts own brand sensor. Was that stupid? Its got a 3 year warranty.

Also I believe that both of my cats are good

Mmm... I'm not a huge fan of cleaning something that is very gunked like that. You risk a large piece of the debris flaking off and getting stuck on a valve seat or something. If it ain't broke, don't fix it.

50sKid Good point! Thanks for the reply and good luck on the rebuild. I may need one in the near future if I keep it.

I added a link in the description

You can get a good one at ECS Tuning.

yes

Your fuel economy takes a hit. I was getting 10mpg until i fixed it

youll use lot more gas!!!!

I'm getting bank 2 sensor errors on mine, is that the downstream sensor?

the leak is probably coming from some hose that lines the engine directly under the intake manifold. Remove the intake manifold assembly and inspect those hoses and temp sensor while you're at it.

Yes. If you have only bank 2 codes like that, it *could* be a bad o2 sensor. If you also have P0171, the problem is likely a vacuum leak. I would encourage you to watch my "Common Vacuum Leaks" video as well as my "How to Diagnose Engine Problems Using Fuel Trims" video for further help/learning on this subject.

For the rear O2s that is ok, you're looking for them to remain slightly rich while the engine is warmed up.

50sKid dude you I would have never guessed what my problem was. There a little fuse box inside that box under the hood by the brake booster. I call it the brains and there was a fuse in there I seen in another video relating to the throttle body that I just wanted to check for shits and giggles. Checked them out and they all light with the tester but on one, one side was dim. Took me about 15 minutes to get the fuse box out and about 20 minutes to open it. If you know about this already I'm wasting my time lol but if you don't you'll find out. Checked the one that was dim, sure enough it was fried. Changed it and started racing hondas! If you want the link of the video just let me know. That's for all your Jason. I appreciate you taking your time and helping me thru my troubles. You da man. Man!

Search for a spark plug socket set on Amazon. There are lots of different ones

Well if you installed headers then you no longer have downstream o2s (sensor 2) right? So now you’ll always have codes.

@@50sKid I installed headers and catalytic converters. But of course they aren’t OEM so yeah.. the O2s probably do not like the catalyst 😂 it’s saying o2 circuit low no activity. Guess I destroyed them somehow. Was a tough job getting the old ones off.

@@rufiorufioo Nah it's not that they "don't like" the catalyst, it's that the electrical circuit is no longer working. Meaning you damaged the wiring somehow during the replacement. You should inspect and find the problem and either fix the wiring or just replace the sensors if that is easier.

@@50sKid alright. Well yesterday driving home from work the check engine light turned off.. and it’s staying off.. man I enjoy the BMW but they are temperamental things.😆 like you said preventative maintenance is key.

Yes, the one under the car

50sKid cheers fella. Much appreciated 👍

What do your fuel trims look like?

i dont remember. i bribed the guy so i get 2 year visa on my car on that service. he said when car is idle, the o2 is way way up. and when he accelerates, it said its normal. so im guessing its the 2 upper sensors?

That's not enough (or even the proper) information to determine what is wrong. Need to look at fuel trims and o2 sensor output to see what's going on.

I was there. It was just going up way out of normal. So far I changed the camshaft sensor, spark plugs and induction coils. So that leaves the o2 sensors and exaust sensor. The car is running rough when idle. Ty!

I know its been a year but do you know the answer ?

E46 rear O2 sensors are Bosch 15109.